CN116611380A - Resistance value calculation method - Google Patents

Abstract

The invention provides a resistance value calculation method. The resistance value calculating method comprises the following steps: calculating a square resistance value based on a square resistance value basic value and a square resistance value correction value, wherein the square resistance value correction value is calculated based on a length direction deviation value of the resistor and a width direction deviation value of the resistor; and calculating the resistance value of the resistor by combining the square resistance value with the length-width ratio, the temperature correction coefficient and the voltage effect coefficient of the resistor. By the configuration, the calculation accuracy is increased by taking the length direction deviation value and the width direction deviation value which affect the resistor into consideration, the problem of inaccurate square resistance value extracted in the prior art is solved, and the accuracy of the resistor resistance value calculation and the circuit simulation result is further improved.

Description

Calculation method of resistance value

technical field

The invention relates to a semiconductor integrated circuit, in particular to a method for calculating the resistance value of a resistor.

Background technique

In semiconductor integrated circuits, resistors are important passive devices in logic and analog circuits. SPICE (Simulation Program with Integrated Circuit Emphasis) is a general-purpose integrated circuit simulation software. The semiconductor industry generally uses SPICE to establish resistor macro models for The purpose of the simulation test is to study the performance of the resistor under various environmental conditions. In the prior art, the resistance model needs to be calculated based on the square resistance value rsh.

When performing resistance modeling, the extraction of the square resistance value rsh in the prior art is generally based on the actual measurement data of the resistance of a certain target size (length L, width W fixed) to directly obtain the value, but the resistance of different lengths and widths There is a significant difference in the measured resistance value of rsh. According to the method of rsh directly taking the measured value of a certain target size resistance, the deviation between the model parameter value of rsh and the actual measured value of resistance of different sizes is large, resulting in the loss of the value of this parameter. Physical meaning, the final resistance model value R obtained is quite different from the actual measurement results, and the simulation results are not accurate enough.

In short, fewer factors are considered in the process of extracting the sheet resistance value in the prior art, which leads to inaccurate extracted sheet resistance values, which further affects subsequent resistance calculation and circuit simulation results.

Contents of the invention

The purpose of the present invention is to provide a resistance value calculation method to solve the problem of inaccurate square resistance values extracted due to the lack of factors considered in the extraction process of square resistance values in the prior art, thereby affecting subsequent resistance resistance values. Problems with value calculations and circuit simulation results.

In order to solve the above technical problems, the present invention provides a method for calculating the resistance value of a resistor, which is used to calculate the resistance value of the resistor, including: calculating the block resistance value based on the basic value of the block resistance value and the correction value of the block resistance value, wherein the block The correction value of the resistance value is calculated based on the deviation value in the length direction of the resistance and the deviation value in the width direction of the resistance; The resistance value of the resistor.

Optionally, the correction value of the square resistance value includes a first correction value, a second correction value and a third correction value, wherein the first correction value is based on the deviation value in the length direction and the deviation value in the width direction jointly calculated aspect ratio deviation correction value; the second correction value is a length deviation correction value calculated based on the length direction deviation value; the third correction value is calculated based on the width direction deviation value Width bias correction value.

Optionally, the step of calculating the square resistance value based on the basic value of the square resistance value and the correction value of the square resistance value includes: calculating the square resistance value based on the following formula: the square resistance value=the basic value of the square resistance value+ The first correction value+the second correction value+the third correction value.

Optionally, before the step of calculating the square resistance value based on the basic value of the square resistance value and the correction value of the square resistance value, the method for calculating the resistance resistance value includes: obtaining experimental data based on actual measurement, and the experimental data includes and the length parameter, width parameter and square resistance value parameter of the described resistance of width; And, described experimental data is substituted into preset formula and obtains the calibration value of the coefficient to be calibrated in described preset formula; Said based on square resistance value basis The step of calculating the square resistance value and the correction value of the square resistance value includes: calculating the square resistance value based on the calibrated preset formula.

Optionally, the step of acquiring experimental data based on actual measurement includes: taking a median of multiple tests as the experimental data.

Optionally, the step of substituting the experimental data into the preset formula to obtain the calibration value of the coefficient to be calibrated in the preset formula is performed based on a planning solution algorithm.

Optionally, the step of substituting the experimental data into the preset formula to obtain the calibration value of the coefficient to be calibrated in the preset formula includes: obtaining the initial value of the coefficient to be calibrated; based on the initial value, setting the table , calculating the estimated value of the resistance value based on the preset formula, and calculating the error between the estimated value and the measured value of the resistance value; based on the preset formula, establishing each in the table The constraint relationship between cells; adjust the value of the coefficient to be calibrated based on the planning solution algorithm to calculate the optimal value of the sum of the errors to reduce the sum of the errors; and, the sum of the errors reaches The value of the coefficient to be calibrated corresponding to the minimum value is set as the calibration value of the coefficient to be calibrated.

Optionally, the preset formula is: rsh = rsh0 + rsh1×(W×1000000-dW)/(L×1000000-dL) + rsh2/(L×1000000-dL) + rsh3/(W×1000000-dL) + rsh3/(W×1000000-dL) dW).

Wherein, rsh is the square resistance value, rsh0 is the basic value of the square resistance value, rsh1 is the aspect ratio deviation correction coefficient, rsh2 is the length deviation correction coefficient, rsh3 is the width deviation correction coefficient, L is the length parameter, W is the width parameter, dL is the deviation value in the length direction, and dW is the deviation value in the width direction.

rsh0, rsh1, rsh2 and rsh3 are configured as the coefficients to be calibrated.

Optionally, the sheet resistance correction value includes a first correction value, a second correction value and a third correction value, and rsh1×(W×1000000-dW)/(L×1000000-dL) is configured as the first correction value A correction value, rsh2/(L×1000000-dL) is configured as the second correction value, and rsh3/(W×1000000-dW) is configured as the third correction value.

Optionally, the step of calculating the resistance value of the resistor by combining the square resistance value with the aspect ratio of the resistor, temperature correction coefficient and voltage effect coefficient includes calculating based on the following formula: R=rsh×L/W× tcoef×(1+rvc1×|v|+rvc2×v^2).

Wherein, R is the resistance value of the resistor, rsh is the square resistance value, L is the length parameter, W is the width parameter, tcoef is the temperature correction coefficient, rvc1 and rvc2 are the voltage effect coefficients, v is the The voltage across the resistor.

Compared with the prior art, in a resistance value calculation method provided by the present invention, the square resistance value is calculated based on the basic value of the square resistance value and the correction value of the square resistance value, wherein the correction value of the square resistance value is based on the resistance Calculate the deviation value in the length direction of the resistance and the deviation value in the width direction of the resistance; and calculate the resistance value of the resistance by combining the square resistance value with the aspect ratio of the resistance, temperature correction coefficient and voltage effect coefficient. Such a configuration takes into account the deviation value in the length direction and the width direction that affect the resistance, increases the calculation accuracy, solves the problem of inaccurate square resistance value extracted in the prior art, and improves the resistance value of the resistance Accuracy of calculation and circuit simulation results.

Description of drawings

Those of ordinary skill in the art will understand that the provided drawings are for better understanding of the present invention, but do not constitute any limitation to the scope of the present invention. in:

FIG. 1 is a schematic flowchart of a method for calculating a resistance value of a resistor according to an embodiment of the present invention.

Detailed ways

In order to make the purpose, advantages and features of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the drawings are all in very simplified form and not drawn to scale, and are only used to facilitate and clearly assist the purpose of illustrating the embodiments of the present invention. In addition, the structures shown in the drawings are often a part of the actual structure. In particular, each drawing needs to display different emphases, and sometimes uses different scales.

As used in the present invention, the singular forms "a", "an" and "the" include plural objects, the term "or" is usually used in the sense of including "and/or", and the term "several" Usually, the term "at least one" is used in the meaning of "at least one", and the term "at least two" is usually used in the meaning of "two or more". In addition, the terms "first", "second "Two" and "third" are used for descriptive purposes only, and should not be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined as "first", "second", and "third" may expressly or implicitly include one or at least two of these features, "one end" and "another end" and "near end" and "near end" "Remote" usually refers to the corresponding two parts, which not only includes the terminal, the terms "installation", "connection", and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection, or Integrate; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediary, can be the internal communication of two components or the interaction relationship between two components. In addition, as used in the present invention, an element is arranged on another element, usually only means that there is a connection, coupling, cooperation or transmission relationship between the two elements, and the relationship between the two elements can be direct or indirect through an intermediate element. connection, coupling, fit or transmission, but cannot be understood as indicating or implying the spatial positional relationship between two elements, that is, one element can be in any orientation such as inside, outside, above, below or on one side of another element, unless the content Also clearly point out. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

The core idea of the present invention is to provide a resistance value calculation method to solve the problem of inaccurate extracted square resistance values due to the lack of factors considered in the extraction process of square resistance values in the prior art, which in turn affects subsequent resistance values. Problems with resistance calculations and circuit simulation results.

Description is made below with reference to the accompanying drawings.

Please refer to FIG. 1. This embodiment provides a method for calculating the resistance value of a resistor, which is used to calculate the resistance value of a resistor, including:

S10. Obtain experimental data based on actual measurement, where the experimental data includes length parameters, width parameters, and square resistance value parameters of resistors with different lengths and widths. The measurement direction of the length and width can be understood according to the common knowledge in the field, and the direction conforming to the relevant setting method or the relevant setting rules can be considered as the length direction and width direction that meet the requirements.

S20. Substituting the experimental data into a preset formula to obtain calibration values of coefficients to be calibrated in the preset formula.

S30. Calculate the square resistance value based on the basic value of the square resistance value and the correction value of the square resistance value, wherein the correction value of the square resistance value is calculated based on the deviation value of the length direction of the resistance and the deviation value of the width direction of the resistance. Step S30 can also be understood as including the following step: calculating the sheet resistance value based on the calibrated preset formula.

And, S40, calculating the resistance value of the resistor by combining the square resistance value with the aspect ratio of the resistor, the temperature correction coefficient and the voltage effect coefficient.

The preset formula can be set according to the description of "calculate the square resistance value based on the basic value of the square resistance value and the corrected value of the square resistance value". In one embodiment, the preset formula is: rsh=rsh0+rsh1×( W×1000000-dW)/(L×1000000-dL) + rsh2/(L×1000000-dL)+ rsh3/(W×1000000-dW).

Wherein, rsh is the square resistance value, rsh0 is the basic value of the square resistance value, rsh1 is the aspect ratio deviation correction coefficient, rsh2 is the length deviation correction coefficient, rsh3 is the width deviation correction coefficient, L is the length parameter, W is the width parameter, dL is the deviation value in the length direction, and dW is the deviation value in the width direction. The methods for extracting the W, L, dL and dW parameters can be understood according to common knowledge in the field, and will not be described here.

rsh0, rsh1, rsh2 and rsh3 are configured as the coefficients to be calibrated.

In the formula, the coefficient of 1,000,000 is for the convenience of coordinating the unit conversion between measurement and calculation, and in different embodiments, it can be changed to 1 or 1,000, etc.

That is, the correction value of the sheet resistance value includes a first correction value, a second correction value and a third correction value, wherein the first correction value is based on the common The calculated aspect ratio deviation correction value; the second correction value is the length deviation correction value calculated based on the length direction deviation value; the third correction value is the width calculated based on the width direction deviation value Bias correction value.

In the above preset formula, rsh1×(W×1000000-dW)/(L×1000000-dL) is configured as the first correction value, and rsh2/(L×1000000-dL) is configured as the first correction value A second correction value, rsh3/(W×1000000-dW) is configured as the third correction value.

In other embodiments, calculation items with the same idea but different forms can also be set according to actual needs.

The above calculation process can also be summarized as calculating the square resistance value based on the following formula: the square resistance value=the basic value of the square resistance value+the first correction value+the second correction value+the third correction value.

In other embodiments, the above calculation items may also be calculated in a combination manner of partial multiplication and partial addition.

In an exemplary embodiment, the step S10 of acquiring experimental data based on actual measurement includes: taking a median of multiple tests as the experimental data. Wherein, the actual test is WAT (Wafer Acceptance Test). In other embodiments, other statistical characteristic values such as mean values may also be chosen for calculation.

The specific manner of step S10 can be set according to common knowledge in the field, for example, adopting an orthogonal experiment design method to select different length and width dimensions.

In one embodiment, taking non-silicided p+ polyns (ppolyns for short) as an example, the formula of the square resistance rsh is constructed, and the square resistance coefficients rsh0, rsh1, rsh2, rsh3 are extracted by using the "programming solution" method.

Solver is part of a set of commands (sometimes called what-if analysis tools). Solver finds the optimal (maximum or minimum) value for a formula in a cell on a worksheet (called the target cell), constrained or limited by the values of other cells on the worksheet. Solver works on a group of cells (called decision variable cells) that participate in the calculation of formulas for target cells and constraint cells. Solver adjusts the values in the decision variable cells to meet the limits on the constraint cells and produce the desired result in the target cells. In simple terms, use Solver to determine the maximum or minimum value of a cell by changing other cells. Step S20 specifically includes the following procedures.

S21. Assign an initial value to the coefficient to be calibrated (the initial value can be set to any number within a certain range according to experience). In this method, the initial value is acquired from outside, and the specific acquisition method is not limited. This example sets rsh0=300, rsh1=-3, rsh2=9, rsh3=29; the values of dW and dL are set as constant values dW=-0.0607, dL=-0.0024 in this example, and the parameters are listed in the table 1 in.

Table 1 Initial values of parameters

S22, the initial sheet resistance value rsh of the sheet resistance model calculated according to the setting of this value, as shown in column 4 in Table 2 below. Among them, Rsh represents the measured square resistance value parameter. Compare the measured square resistance value parameter Rsh with the initial square resistance value rsh of the square resistance model, calculate the difference percentage abs(rsh-Rsh)/Rsh, and sum the calculated differences to obtain the difference value and items.

Table 2 The rsh value and error calculated based on the initial value

S23, use the "programming solution" method to calculate the optimal value of 57.24% of the difference summation item in Table 2, because this difference summation item is constrained by the initial square resistance value rsh of the square resistance model in Table 2, and the square resistance The sheet resistance value rsh of the model is constrained by the sheet resistance coefficients rsh0, rsh1, rsh2, rsh3, so when finding the minimum value of the difference summation term, the values of rsh0, rsh1, rsh2, rsh3 will also change accordingly. The minimum value of the difference summation item obtained at the end of this column is 11.24%, and the square resistivity rsh0, rsh1, rsh2, rsh3 are also extracted. In this example, the extracted square resistivity rsh0=318.32149, rsh1=- 13.17427, rsh2=9.000006964, rsh3=29.00282154. According to the square resistivity value, the square resistance values rsh of different sizes in the resistance model can be calculated. As shown in Table 3 and Table 4 below.

Table 3 Optimized coefficients

Table 4 The rsh value and error calculated based on the optimized coefficient

It can be seen from Table 4 that the error between the rsh calculated based on the optimized coefficient and the actual Rsh is small. The value of each parameter in Table 3 can also be regarded as the calibration value of the coefficient to be calibrated. From the results in Table 4, it can be reasonably inferred that when the parameters in Table 3 are used for calculation, the calculation results will be more in line with the actual situation, thereby solving the problems existing in the prior art.

The above process can also be summarized as follows: the step of substituting the experimental data into the preset formula to obtain the calibration value of the coefficient to be calibrated in the preset formula is performed based on a planning solution algorithm.

And, the step of substituting the experimental data into the preset formula to obtain the calibration value of the coefficient to be calibrated in the preset formula includes: obtaining the initial value of the coefficient to be calibrated; based on the initial value, setting a table, based on The preset formula calculates the estimated value of the resistance value of the resistor, and calculates the error between the estimated value and the measured value of the resistance value; based on the preset formula, each cell in the table is established The constraint relationship among them; adjust the value of the coefficient to be calibrated based on the planning solution algorithm to calculate the optimal value of the sum of the errors to reduce the sum of the errors; and, the sum of the errors reaches a minimum value When the corresponding value of the coefficient to be calibrated is set as the calibration value of the coefficient to be calibrated.

Further, the step of calculating the resistance value of the resistor by combining the square resistance value with the aspect ratio of the resistor, temperature correction coefficient and voltage effect coefficient includes calculating based on the following formula: R=rsh×L/W×tcoef ×(1+rvc1×|v|+rvc2×v^2).

Wherein, R is the resistance value of the resistor, rsh is the square resistance value, L is the length parameter, W is the width parameter, tcoef is the temperature correction coefficient, rvc1 and rvc2 are the voltage effect coefficients , v is the voltage received by the resistor.

That is to say, in an embodiment, in conjunction with steps S30 and S40, the following formula can be used to calculate the resistance value of the resistor.

R=(rsh0 + rsh1×(W×1000000-dW)/(L×1000000-dL) + rsh2/(L×1000000-dL) + rsh3/(W×1000000-dW))×L/W×tcoef× (1+rvc1×|v|+rvc2×v^2).

To sum up, in the method for calculating the resistance value provided by this embodiment, the square resistance value is calculated based on the basic value of the square resistance value and the correction value of the square resistance value, wherein the correction value of the square resistance value is based on the value of the resistance Calculate the deviation value in the length direction and the deviation value in the width direction of the resistance; and calculate the resistance value of the resistance by combining the square resistance value with the aspect ratio of the resistance, temperature correction coefficient and voltage effect coefficient. Such a configuration takes into account the deviation value in the length direction and the width direction that affect the resistance, increases the calculation accuracy, solves the problem of inaccurate square resistance value extracted in the prior art, and improves the resistance value of the resistance Accuracy of calculation and circuit simulation results.

The above description is only a description of the preferred embodiments of the present invention, and does not limit the scope of the present invention. Any changes and modifications made by those of ordinary skill in the field of the present invention based on the above disclosures belong to the protection scope of the technical solution of the present invention.

Claims (10)

1. A resistance value calculation method for calculating a resistance value of a resistor, comprising:

calculating a square resistance value based on a square resistance value basic value and a square resistance value correction value, wherein the square resistance value correction value is calculated based on a length direction deviation value of the resistor and a width direction deviation value of the resistor; the method comprises the steps of,

and calculating the square resistance value by combining the aspect ratio, the temperature correction coefficient and the voltage effect coefficient of the resistor.

2. The method of calculating a resistance value according to claim 1, wherein the sheet resistance value correction value includes a first correction value, a second correction value, and a third correction value, wherein,

the first correction value is an aspect ratio deviation correction value calculated based on the length direction deviation value and the width direction deviation value;

the second correction value is a length deviation correction value calculated based on the length direction deviation value;

the third correction value is a width deviation correction value calculated based on the width direction deviation value.

3. The method of calculating a resistance value according to claim 2, wherein the step of calculating a sheet resistance value based on the sheet resistance value base value and the sheet resistance value correction value includes: the sheet resistance value is calculated based on the following formula: the square resistance value=the square resistance value basic value+the first correction value+the second correction value+the third correction value.

4. The resistance value calculation method according to claim 1, wherein before the step of calculating the sheet resistance value based on the sheet resistance value base value and the sheet resistance value correction value, the resistance value calculation method includes:

acquiring experimental data based on actual measurement, wherein the experimental data comprises length parameters, width parameters and square resistance value parameters of the resistors with different lengths and widths; the method comprises the steps of,

substituting the experimental data into a preset formula to obtain a calibration value of a coefficient to be calibrated in the preset formula;

the step of calculating the square resistance value based on the square resistance value basic value and the square resistance value correction value comprises the following steps: and calculating the square resistance value based on the calibrated preset formula.

5. The method of calculating resistance values according to claim 4, wherein the step of acquiring experimental data based on actual measurement includes: the median was taken as the experimental data for multiple tests.

6. The method according to claim 4, wherein the step of substituting the experimental data into a preset formula to obtain the calibration value of the coefficient to be calibrated in the preset formula is performed based on a planning solution algorithm.

7. The method according to claim 6, wherein the step of substituting the experimental data into a preset formula to obtain the calibration value of the coefficient to be calibrated in the preset formula comprises:

acquiring an initial value of the coefficient to be calibrated;

based on the initial value, a table is set, an estimated value of the resistance value of the resistor is calculated based on the preset formula, and an error between the estimated value and an actual measured value of the resistance value of the resistor is calculated;

based on the preset formula, establishing a constraint relation among cells in the table;

adjusting the value of the coefficient to be calibrated based on a planning solving algorithm, and performing optimal value calculation on the sum of errors to reduce the sum of errors; the method comprises the steps of,

and setting the value of the coefficient to be calibrated corresponding to the minimum value of the error sum as the calibration value of the coefficient to be calibrated.

8. The method of claim 6, wherein the predetermined formula is:

rsh = rsh0 + rsh1×(W×1000000-dW)/(L×1000000-dL) + rsh2/(L×1000000-dL) + rsh3/(W×1000000-dW)；

wherein rsh is the square resistance value, rsh0 is the square resistance value basic value, rsh1 is an aspect ratio deviation correction coefficient, rsh2 is a length deviation correction coefficient, rsh3 is a width deviation correction coefficient, L is the length parameter, W is the width parameter, dL is a length direction deviation value, dW is the width direction deviation value;

rsh0, rsh1, rsh2 and rsh3 are configured as the coefficients to be calibrated.

9. The resistance value calculation method according to claim 8, wherein the sheet resistance value correction values include a first correction value, a second correction value, and a third correction value, rsh1× (w×1000000-dW)/(l×1000000-dL) is configured as the first correction value, rsh 2/(l×1000000-dL) is configured as the second correction value, and rsh 3/(w×1000000-dW) is configured as the third correction value.

10. The method of claim 1, wherein the step of calculating the square resistance value in combination with the aspect ratio, the temperature correction coefficient, and the voltage effect coefficient of the resistor comprises calculating the resistance value of the resistor based on the following formula:

R=rsh×L/W×tcoef×(1+rvc1×|v|+rvc2×v^2)；

wherein, R is the resistance value of the resistor, rsh is the square resistance value, L is the length parameter, W is the width parameter, tcoef is the temperature correction coefficient, rvc1 and rvc2 are the voltage effect coefficient, and v is the voltage received by the resistor.